Office History

Founded in 1856, the County of San Mateo, with the San Francisco Bay and Pacific Ocean making up the eastern and western most boundaries, covers over 500 square miles consisting of densely populated cities and rural farmland. Over 90% of the county's 720,000 citizens reside in 20 incorporated cities.

Today, the Sheriff's Office has over 600 sworn and civilian personnel who provide various law enforcement services to all cities in the County, including contract police services for the Peninsula Corridor Joint Powers Board (Caltrain), the San Mateo County Transit District (SamTrans), the City of San Carlos, Eichler Highlands and the towns of Woodside and Portola Valley. The Sheriff also provides investigative services to the San Francisco International Airport.

Early Sheriffs

In 1857, John W. Ackerson was elected as the first Sheriff of San Mateo County and served for two years. The first courthouse and jail was J.V. Diller's warehouse on Redwood Creek. In 1858 a new courthouse and jail were located on Broadway Avenue in Redwood City.

Who were our early sheriffs? John Ackerson worked for a lumber company and after leaving the Sheriff's Office, went to Washington's Puget Sound where he was very successful in the logging and lumber business. The second sheriff, Silas Hovius, who also served for two years, was a coast side farmer. In 1865, Thomas W. Lathrop was elected sheriff and was well known as a first lieutenant of the Jefferson Cavalry, a local militia. There were concerns that the Confederate army would come through San Mateo County on their way to the San Francisco Mint, where they wanted to stop the flow of gold to the Union cause. The confederate army was stopped 80 miles from the California border.

New Era

In the 1930's, Sheriff James McGrath established a precedent by putting his only night patrol deputy in a uniform. Deputy John O'Brien reported for duty wearing a Khaki shirt, olive drab trousers, and police cap and black leather coat with a gold badge. McGrath stayed in office for four terms, the longest in our history.

Modern Law Enforcement with Sheriff Whitmore

In 1951, Earl B. Whitmore was elected sheriff and brought modern police standards to the Sheriff's Office. At the time, Sheriff Whitmore, who had been a sergeant for the Redwood City Police Department, was the youngest sheriff in the United States, being 34 years of age. He was an accomplished horseman and was the marshal in the Annual Tournament of Roses parade in Pasadena, California. He graduated from the 52nd Session of the FBI National Academy in 1953.

Prior to 1951, the Sheriff was the only ranking officer in the department, but Sheriff Whitmore established a new rank system consisting of a Chief Deputy Sheriff, Chief Civil Deputy, Chief Jailer, Captain of the Criminal Division, Lieutenant in charge of the Juvenile Division, Supervisor of Records and Identification Bureau, six Inspectors and four Patrol Sergeants. By 1953, the Sheriff's Office increased in size from 54 to 91 employees.

Sheriff Whitmore opened sub-stations at Mills Field (San Francisco Airport), Half Moon Bay, Sharp Park (Pacifica) and Brisbane to provide greater law enforcement coverage throughout the county. The first resident deputy was in Pescadero, which was the center of the south coast area, approximately 200 square miles. All patrol cars were equipped with police radios.

Crash Wagons

One of the most unique innovations was the “Crash Wagon.” Five ambulances were outfitted with police protection, investigation and rescue equipment. Staffed with a deputy sheriff and an ambulance driver, these vehicles patrolled the county on a 24/7 basis and were able to respond to any incident. Sheriff Whitmore received national recognition, including United-International News Reels' 1954 film “Crash Wagons.” It was distributed throughout the United States and in 37 foreign countries. A letter from J. Edgar Hoover, commending Sheriff Whitmore, was included in the film.

Crime Lab

Sheriff Whitmore established a Crime Lab equipped with the latest and finest equipment for detection and examination of evidence. The services of the County Crime Lab were made available to all other agencies in San Mateo County.


San Mateo County was one of the first in the state to train deputies in the field of narcotics, working with local law enforcement apprehending “dope peddlers and users.” Sheriff Whitmore assigned four deputies to attend service groups and other organizations in the county giving talks on narcotics and to acquaint the general public with the “devil's weed.” It later evolved into the Bureau of Special Services, which investigated vice, narcotics, gambling and the growing juvenile delinquency problem.

Work Furlough Program

Started in 1966, the Sheriff's Work Furlough Program was the first of it's kind in the United States, housing 110 inmates. Inmates that are convicted of minor crimes and employed, can apply to this program, where they attend work during the day and stayed at the facility each night. They paid for their own incarceration, saving the taxpayers thousands of dollars each year. The deputies at Work Furlough were trained in rehabilitation counseling and each was assigned 12 inmates for individual and group counseling.

Sheriff Whitmore Retires

After 22 years as Sheriff, Earl Whitmore retired in 1973. The Board of Supervisors appointed John R. McDonald Sheriff, who at that time was the current Chief of Police for the city of Redwood City. He was Sheriff for 10 years, retiring before the end of his term in 1983.

Lieutenant Brendan Maguire, along with several other lieutenants and captains in the Sheriff's Office, ran for sheriff in a special election. Brendan Maguire won the election and became Sheriff in 1983. He died of a heart attack in April of 1986, which was during a regular election year. The only other candidate running against Sheriff Maguire was a man named Jim White, who had no prior association with the Sheriff's Office. The election was in June, just two months after Sheriff Maguire's death and members of the Sheriff's Office pulled together campaigning for Sheriff Maguire. Sheriff Maguire was re-elected posthumously and Leonard Cardoza, the current Undersheriff, was appointed until a special election could be held.

Several captains and lieutenants ran for Sheriff in a special election, but Leonard Cardoza was elected and continued as Sheriff until he retired in 1993.

Lieutenant Don Horsley was elected as Sheriff in 1993. A police officer from the Pacifica Police Department, he started with the Sheriff's Office in 1972.

Sheriff Horsley's Undersheriff, Greg Munks ran unopposed in the 2006 elections shortly following Sheriff's Horsley's retirement and was sworn in as Sheriff on January 8, 2007. Former Sheriff Munks ran unopposed again in his second term, and currently serves as the Sheriff of San Mateo County.

Last update: December 1, 2010